The viscoelastic properties of synthetic polyisoprenes （PI） reinforced by white carbon black （WCB） have been investigated and compared with WCB reinforced natural rubber （NR）, including cure characteristics, phy...The viscoelastic properties of synthetic polyisoprenes （PI） reinforced by white carbon black （WCB） have been investigated and compared with WCB reinforced natural rubber （NR）, including cure characteristics, physio-mechanical and dynamic mechanical properties. Compared with NR, PI loaded with the same amount of WCB （PI/WCB） exhibited shorter scorch time and optimal cure time, indicating that WCB fillers are comparatively easier to conjugate with PI. The tensile strength and elongation at break decreased with WCB filling in both PI and NR vulcanizates. The hardness of the rubber vulcanizates increased with the WCB filling in the rubber matrix. PI/WCB blends exhibited smaller hardness data, lower tensile strength, as well as lower elongation at break and tensile stress. Increasing the amount of WCB in rubber matrix induced the Payne effect. However, the Payne effect is much more obvious for the PI/WCB system, and PI/WCB also displayed higher storage modulus whereas lower loss modulus and loss tangent than NR/WCB, which could all be attributed to the poor dispersibilities of WCB in the PI matrix.展开更多
Cis-1, 4-polybutadiene polymerized with lanthanide coordination catalyst (Ln-PB) has been developed in China. It possesses a cis-content greater than 97%, and nearly 100% recently (Table 1). The Ln-PB has been charact...Cis-1, 4-polybutadiene polymerized with lanthanide coordination catalyst (Ln-PB) has been developed in China. It possesses a cis-content greater than 97%, and nearly 100% recently (Table 1). The Ln-PB has been characterized and compared with other PB’s polymerized with Co-, Ni-and U-catalytic systems. Most of the characterization methods for structure and viscoelastic properties are similar to those reported for Ni-PB^2.展开更多
基金financially supported by the National Basic Research Program of China(No.2010CB934700)
文摘The viscoelastic properties of synthetic polyisoprenes （PI） reinforced by white carbon black （WCB） have been investigated and compared with WCB reinforced natural rubber （NR）, including cure characteristics, physio-mechanical and dynamic mechanical properties. Compared with NR, PI loaded with the same amount of WCB （PI/WCB） exhibited shorter scorch time and optimal cure time, indicating that WCB fillers are comparatively easier to conjugate with PI. The tensile strength and elongation at break decreased with WCB filling in both PI and NR vulcanizates. The hardness of the rubber vulcanizates increased with the WCB filling in the rubber matrix. PI/WCB blends exhibited smaller hardness data, lower tensile strength, as well as lower elongation at break and tensile stress. Increasing the amount of WCB in rubber matrix induced the Payne effect. However, the Payne effect is much more obvious for the PI/WCB system, and PI/WCB also displayed higher storage modulus whereas lower loss modulus and loss tangent than NR/WCB, which could all be attributed to the poor dispersibilities of WCB in the PI matrix.
文摘Cis-1, 4-polybutadiene polymerized with lanthanide coordination catalyst (Ln-PB) has been developed in China. It possesses a cis-content greater than 97%, and nearly 100% recently (Table 1). The Ln-PB has been characterized and compared with other PB’s polymerized with Co-, Ni-and U-catalytic systems. Most of the characterization methods for structure and viscoelastic properties are similar to those reported for Ni-PB^2.
